Process for impregnating textile fabrics



Patented Dec. 24, 1935 UNITED STATES PATENT OFFICE FABR Sidney G.Osborne, New York, N. Y., assignor to Hooker Electrochemical Company,New York, N. Y., a corporation of New York No Drawing. Application March17, 1933, Serial No. 661,353

17 Claims.

More particularly, my invention relates to processes for weighting andmordanting of textiles, including silk and cotton, by impregnating withmetallic salts, such as chlorides of tin, an-

timony, etc., and has for its object to render the cheaper salts moreavailable than hitherto, to reduce the waste of these salts and toimprove the quality of the product.

, Although a great number of processes for impregnating fabrics havebeen proposed, all of them depend upon treating the fabric with asolvent carrying in solution a metallic salt, fixing the metal byconverting it to an insoluble compound and washing out the by-products.A considerable variety of metals, such as tin, lead, antimony, aluminum,barium, zirconium, etc., have been experimented with. Likewise, a numberof different salts, such as the sulphate, chloride, formate, lactate,tartrate, oxalate, etc., have been tried or proposed. However, ninetyper cent of all silk weighting is carried out today by the use of-tintetrachloride. The solvent used has invariably been water, andhydrolysis has been the means depended upon for fixing the metal.Hydrolysis converts the salt into the oxide, the original acid radicalreappearing as free acid, which must be neutralized and removed bywashing. A further treatment with disodium phosphate and sodium silicateserves to convert the metal into so complex insoluble salts that havebeen found to impart desirable characteristics to textile fabrics.

Since the process above described depends upon hydrolysis, it will beobvious that an inhibitor of hydrolysis must be employed when making upthe water solution. For this purpose it is common practice to acidifywith the acid of the salt used. Thus if the salt is a chloride, it isusual to acidify with muriatic acid. Common salt is also sometimesadded. These materials may have a deleterious effect upon the fabric.Before hydrolysis can take place, the inhibitor must be removed. This iscommonly accomplished by washing; but it is obviously impossible to Washout the inhibitor without at the same time carrying away some of themetallic salt. In practice, it is quite common to lose thirty per centof the metal in this way.

Tin chloride is a relatively expensive material. Other cheaper chloridesare available, such as antimony chloride, but this salt hydrolizes soreadily that the inhibitor must be in greater concentration and thepossible injury to the fabric may be proportionately increased.

To obviate these difficulties, I substitute for water a non-aqueous ororganic solvent, prefer ably volatile. Such solvents have greaterpenetrating power, especially when there is a water repellent animal orvegetable wax or oil present in the fibre, as is usually the case. Theydo not injure the fabric; neither do they react with the 5 salt to causehydrolysis. Consequently, no inhibitor is necessary and the injury tothe fabric from acid inhibitors is avoided. Moreover, since there is noinhibitor to be washed out, the waste of metallic salt in this step iseliminated. In 10 my preferred process, it is only necessary, afterimpregnation, to evaporate ofi the solvent and expose the fabric to theaction of water, which may be vapor or steam. This of course carriesnothing out of the fabric. The acid formed by 5 the hydrolysis may thenbe washed out in the usual way, the metal at this stage having beenconverted into an insoluble compound. Before impregnating-in accordancewith my process, the

fabric may be soaked in an alkaline solution and 20 dried, but I preferto use an alkaline vapor, thus neutralizing the acid as formed. For thispurpose, the vapor from an alkaline solution, such as a solution ofammonia or amines may be used;

or gaseous ammonia may be mingled with the 25 water vapor. In the lattercase, the ammonium chloride formed is easily removed by washing. Thisprocess may be repeated until the desired weighting'eflect has'beenattained. The treatment with disodium phosphate and sodium silicate maythen be proceeded with if desired.

My process therefore permits the use of the relatively cheap antimonychloride (which costs less than half as much as tin chloride) withoutany waste in the hydrolysis step or exposure of the 35 fabric to acideither before or during hydrolysis, and thus results in a stronger,better and cheaper product.

The organic solvent used in carrying out my rocess may be any of thewell known organic 40 solvents, such as acetone, methanol, carbontetrachloride or a hydrocarbon, such as benzol, toluol or gasoline.Chlorinated hydrocarbons are for some purposes advantageous overnon-chlorinat- 45 ed hydrocarbons. In general, chlorination ofhydrocarbons reduces fire hazard and toxicity; moreover, the solventproperties may be distinctly improved for specific purposes, such as forcertain waxes. Examples of chlorinated hydrocarbons 50 having superiorsolvent properties are monochlor benzol, trichlor ethylene, ethylenedichloride, etc. Carbon tetrachloride is also an example of achlorinated hydrocarbon. It is to be understoodthat chlorinatedhydrocarbons are considered as 55 hydrocarbons within the meaning ofthis specification and the subjoined claims.

It will be obvious that my process is equally applicable to weighting ofsilk and mordanting of cotton, the advantages being substantially thesame in either case.

The essence of my invention resides in the avoidance of a solvent thatreacts with the salt to cause hydrolysis. Any non-aqueous solventfulfills this condition. I do not wish to be limited, therefore, to onemetal or to any particular metal, salt or solvent, so long as thesolvent fulfills the condition just enunciated. For example, a solventthat, of itself, reacted with the salt or salts but only under easilycontrollable conditions, such as exposure to the air, would likewisefall within the scope of my invention.

Neither do I wish to be limited to hydrolysis as the means of fixing themetal in the fabric, since any method of causing conversion to the oxideor any other insoluble compound will produce the desired result. Forexample, when ther'e is no inhibitor present, exposure to heat, air or anon-aqueous alkali may accomplish the pur-v hydrolysis to anon-water-soluble compound of the metal.

2. The process of impregnating textile fabrics which comprises immersingthe fabric in an organic solvent inert with respect to said fabric andcarrying in solution a metallic salt, evaporating on the solvent,exposing the salt to a hydrolizing condition and washing the fabric.

3. The process of impregnating textile fabrics which comprises immersingthe fabric in an organic solvent inert with respect to said fabric andcarrying in solution a metallic salt, evaporating ofi the solvent,exposing the fabric to the action of water vapor, whereby the salt ishydrolized to an oxide of the metal, and washing the fabric.

4. The process of impregnating textile fabrics as defined in claim 3 inwhich the vapor is derived from an alkaline aqueous solution.

5. The process of impregnating textile fabrics as defined in claim 3 inwhich the vapor is rendered alkaline by means of ammonia.

- 6. The processof impregnating textile fabrics as defined, in claim 1in which the solvent is a hydrocarbon.

7. The process of impregnating textile fabrics which comprises immersingthe fabric in an organic solvent carrying in solution a salt of thelead-tin-antimony group of metals, evaporating 01f the solvent andconverting the salt by hydrolysis to a non-water-soluble compound of themetal.

8. The process of weighting silk which comprises immersingthe silk in anorganic solvent carrying in solution antimony chloride, evaporating offthe solvent and exposing the silk to the action of water vapor andammonia and washing 5 the silk.

9. The process of weighting silk which comprises immerslng the fabric ina substantially water-free solvent carrying in solution a salt of arelatively heavy metal and converting the salt by hydrolysis to anon-water-soluble compound of the metal. 1

'10. The process of impregnating textile fabrics as defined in claim 1followed by immersion in a bath of disodium phosphate, washingand-immersing in a bath of sodium silicate.

11. The process of weighting silk which comprises immersing the silk inan o c solvent carrying in solution a salt of the ad-tin-antimony groupof metals, evaporating off the sol- 3 vent and converting the salt byhydrolysis to a non-water-soluble compound of the metal.

12. The process of weighting textile fabrics which comprises penetratingthe fibers thereof with an organic solvent carrying in solution a assalt of a relatively heavy metal and fixing the metal in the fibers byconverting the salt by hydrolysis to an insoluble compound of the metal.

13'. The process of treating textile materials to 0 increase the weightthereof which comprisesimmersing the material in a non-aqueous solventcarrying in solution a salt of a metal, evaporating off the solvent, andfixing the metal in the material by hydrolysis and reaction withcompounds 5 forming water-insoluble compounds with said metal. l

"14. The process of treating textile materials which comprises immersingthe material in a bath consisting of a salt of a metal dissolved in 40non-aqueous solvent, evaporating off the solvent, and fixing the metalin the material by hydrolysis and reaction with salts formingwater-insoluble compounds with said metal.

15. The process of treating textile materials which comprisesimpregnating the material with a salt of a metal in a non-aqueoussolvent, evaporating of! the solvent and converting the salt to anon-water-soluble compound of the metal by hydrolysis in the presence ofbasic material.

16. The process of treating textile materials which comprisesimpregnating with a salt of a metal in a non-aqueous solvent,evaporating off the solvent and. converting the salt to anonwater-soluble compound of the metal by hydrolysis in presence of analkali.

17. The process of treating textile materials which comprisesimpregnating the material with a salt of a metal in a non-aqueoussolvent, evaporating off the solvent, and converting the salt

